Will Berkeley has posted comments on this change. ( http://gerrit.cloudera.org:8080/12614 )
Change subject: KUDU-2711 (part 2): use a RWMutex for TSDescriptor ...................................................................... Patch Set 1: (2 comments) http://gerrit.cloudera.org:8080/#/c/12614/1//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/12614/1//COMMIT_MSG@12 PS1, Line 12: This patch changes the spinlock to a RWMutex. > Curious why you chose RWMutex and not rw_spinlock. There's no I/O here, so I agree with that. I tested with both an RWMutex and an rw_spinlock on ve0518 and the rw_spinlock was about 5% better. http://gerrit.cloudera.org:8080/#/c/12614/1//COMMIT_MSG@45 PS1, Line 45: 99.99% = 10048 > Interesting that the latency at the end of the tail increased slightly. Is Not clear. In general, the variance of some "extreme" sort of sample variable can be (a lot) higher than the variance of a measure of central tendency like the median or mean. See e.g. https://stats.stackexchange.com/questions/15970/what-is-the-variance-of-the-maximum-of-a-sample, which doesn't cover extreme percentiles but it does talk about the maximum and the order statistics. -- To view, visit http://gerrit.cloudera.org:8080/12614 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Id48635e49f11d20fa1802b17a3ff5771632dfd01 Gerrit-Change-Number: 12614 Gerrit-PatchSet: 1 Gerrit-Owner: Todd Lipcon <[email protected]> Gerrit-Reviewer: Adar Dembo <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Will Berkeley <[email protected]> Gerrit-Comment-Date: Thu, 07 Mar 2019 22:44:51 +0000 Gerrit-HasComments: Yes
